I have my master lightroom catalog on my desktop. Is there a way to syncrhonize the desktop master lightroom file with my laptop lightroom?
There's no special way.
You can use File > Import from Another Catalog to bring one catalogue's work into the other. File > Export to Catalog is the corresponding command which lets you create a small catalogue limited to the images you select. You might then copy this to the other computer and use the Import from Another Catalog command to bring just those images into the other catalogue. But it is a manual process.
If you continually switch between these two computers, you might consider having a single catalogue which you keep on an external hard drive or on Dropbox.